How do I freeze all players at the same time rather than individually?

I'm trying to create a script where all players apart from the user who casted it, freeze at the same time. However, at the moment; The script freezes people individually, then after they unfreeze, moves onto the next person and then the next etc. But I want everyone to freeze at the same time otherwise the color correction doesn't match up..

Any ideas?

My code:

game.ReplicatedStorage.Freeze.OnServerEvent:Connect(function(player)
local TweenService = game:GetService("TweenService")
local part = game.Lighting.ColorCorrection
local Info = TweenInfo.new(
    10,
    Enum.EasingStyle.Linear,
    Enum.EasingDirection.Out,
    0,
    true,
    0)
local Goals ={
  Saturation = -1}
  local tween = TweenService:Create(part,Info,Goals)
  tween:Play()

  for _, child in ipairs(game.Players:GetChildren()) do
    if child.Name ~= player.Name then

      local Them = child.Character
wait()

      for _, NotThem in ipairs(Them:GetChildren()) do
    wait()
        if NotThem.ClassName == "Part" or NotThem.ClassName == "MeshPart" then
          NotThem.Anchored = true
        end
      end
wait(20)
for _, NotThem in ipairs(Them:GetChildren()) do
    wait()
        if NotThem.ClassName == "Part" or NotThem.ClassName == "MeshPart" then
          NotThem.Anchored = false
game.Lighting.ColorCorrection.Saturation = 0
        end
      end
    end
  end
  end)

Thank you.